1. Field
The present disclosure relates generally to measurement systems and in particular to a method and apparatus for measuring a part. Still more particularly, the present disclosure relates to a method and apparatus for measuring features on a part.
2. Background
Maintenance, modification, and/or repair of aircraft may be commonly performed. These operations may be performed on commercial, military, and other suitable types of aircraft. During these types of operations, a new part may be created to replace a part that may be worn out and/or obsolete.
Additionally, new parts may be added to existing parts to change the functionality, operation, and/or performance of an aircraft. New parts may be created to mate with existing parts. The features that may be used to mate one part with another part include, for example, without limitation, holes and/or pins.
For example, without limitation, a new part may have a pattern of holes and/or hole diameters that may be required to match those in an existing part. The holes in the existing part may differ from design specifications due to manufacturing tolerances and/or wear occurring from use of the part.
As a result, it may be important to accurately measure mating features such as, for example, without limitation, hole patterns and/or locations and other parameters about holes from the existing part. One technique to identify hole patterns and/or other information about holes may be photogrammetry. Photogrammetry may identify geometric properties about objects using photographic images. For example, without limitation, hole patterns may be identified through the use of photogrammetry.
Measurement targets may be placed into the holes of the part. These measurement targets may include a feature that may allow for an accurate identification of the location of the holes. A measurement target may comprise a feature attached to a shaft. The feature may be, for example, without limitation, an object with a circle having a particular color and/or reflectivity. The shaft may be placed into the hole in the part. The center of the circle may be in line with the centerline of the shaft placed into the hole.
With this type of measurement, it may be important to identify the orientation of the hole, the centerline of the hole, and other information about the hole using these measurement targets.
Difficulties may be encountered in obtaining accurate measurements of a shaft for a measurement target does not correctly fit into a hole. A shaft may not correctly fit into the hole if a shaft is too small or too large. The shaft may be too small in diameter if the measurement target sits within the hole such that the center of the circle is not in line with the centerline of the hole.
Currently, measurement targets with different sized shafts may be used to compensate for different sized holes. Even with different sized shafts, it may not be possible to obtain an exact fit between a shaft and a hole. As a result, errors in measurements may occur that may result in the creation of a new part that may not correctly match an existing part.
Therefore, it would be advantageous to have a method and apparatus that overcomes the issues discussed above, as well as other possible issues.